Screw-propeller.



E. ussEY.

SCREW PROPELLER.

APPLICATION FILED NOV. 22, |913.

1,175,408., Patented Mar. 14, 1916.

Figi- "MMM THE COLUMBIA PLANOGRAPH C0.. WASHINGTON, D. C.

'EINIIED @FIXE PATENT IPIPI@E f EVEEETT E, EUSSEY, CE MALDEN, MASSACHUSETTS, ASsIeNoE To ALEXANDER r. EEowNE, TRUSTEE, or CAMBRIDGE, MASSACHUSETTS.

SCREW-PROPELLER.

tiranos.

Application filed November 22, 1913.

To @ZZ whom t may concern.'

Ide 1t known that I, EVERETT E. BUssEY, a cltizen of the United States, and a resident of Malden, in the county of Middlesex and and its object is to improve and simplifyk the construction thereof and increase they eiiiciency of the same in the manner hereinafter set forth.

One embodiment of my invention is illustrated in the accompanying drawings, in which- Fgure 1 is a side elevation showing a portion of the stern of a ship with my improved propeller secured in position and Fig. 2 is avertical section.

In the particular drawings selected for more fully disclosingy my invention, l represents the stern of the ship, to the sternpost 2 of which is secured the stuffing-box 3 with its packing 4 and cap 5 for the propeller shaft 6 which extends rearwardly through the stern-post and is secured in any suitable manner as by the nuts 7 to the boss 8. The boss S consists of the frustum of a cone having a smooth unbroken exterior surface to which the blades 11 are secured, and as shown in the present instance, said blades are preferably cast integral with said frustum. A convenient means for attaching the frustum to the shaft consists in providing the former with a base 8 and a centrally-disposed hub 9, through which the shouldered shaft extends and to which it is secured by the nuts 7. It will be obvious, however, that various other means may be employed for attaching the frustum to the shaft. Secured to the outer end of said frus tum is a cone-shaped cap 10, having a smooth unbroken surface from base to apex, said cap and frustum constituting a cone having a smooth unbroken surface from its base 8 to its apex. Preferably the cap is threaded to the interior of the outer edge of the boss, said threads being cut in the opposite sense to that of the rotation of the propeller.

I prefer to interpose between the boss and the stern of the vessel a cylinderlQ, the

s Specification of Letters Patent.

Patented Mar. 14, 1916.

Serial No. 802,411.

rearward end of which preferably overlaps the forward end of the boss, and the forward end of which is secured to the stern preferably as shown in the present case by cutting a slot in the lower portion of the cylinder, so that said lower portion will straddle the stern-post, as shown at 13, and passing screws or nails l5 through the flanged forward edges 14 of the cylinder into the stern.

By means of the construction above described I eliminate the drag caused by the ineective inner portions of the blades and the water-resistance caused by the base 8', the entire surface of each blade from the boss to the tip thereof being effective for propulsion and the i'nclosing cylinder 12 preventing the drag on the ship that otherwise would result from the contact 0f the vbase 8 with the water.

I am aware that heretofore attempts have been made to suppress the ineffective inner ends of the blades by securing the blades to a cylindrical boss of large diameter; but I have found that such construction is in effective in practice, whereas by vmeans of a propeller constructed in accordance with the present invention I have obtained an increase in eilicieney of over thirty per cent. Such increase in efciency is due in large part to the employment of a boss consisting of the frustum of a cone instead of a cyl inder and a cone-shaped cap for said frustum, the external surface of the cone so formed being smooth and unbroken from base to apex, and also to the cylinder interposed between the stern of the vessel and the base of the boss.

It will be obvious that various modifications may be made in the apparatus specifically described without departing from the principle of my invention.

I claim:

In a propeller, a boss consisting of a frustum of a Cone and a base therefor, a hub arranged at right angles to said base and ing through said hub, means for attaching subscribed myname this 21st day of Nosaid hub to said shaft, and a cylinder interveniber, 1913. r

osedbetween saidpropeller and the stei'nA m s gf said Vessel, said cylinder having its rear- EVEBETL Ward endjoverlapping said boss and its for- Witnesses: f Ward end secured to the stern'of said Vessel. GEO. H. WVOODWORTH,

In testimony whereof, I vhave hereunto E. B. yToMLlNsov.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Wshngton, D. C. 

